M95040-DRDW4TP datasheet(21/41 Pages) STMICROELECTRONICS

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M95040-A125 M95040-A145

Instructions

4.7

Read Identification Page (RDID)

The Read Identification Page instruction is used to read the Identification Page (additional

page of 16 byte which can be written and later permanently locked in Read-only mode).

The Chip Select (S) signal is first driven low, the bits of the instruction byte and address

bytes are then shifted in (MSB first) on Serial Data input (D). Address bit A8 must be 0 and

the other upper address bits are Don't Care (it might be easier to define these bits as 0, as

shown in Table 6). The data byte pointed to by the lower address bits [A4:A0] is shifted out

(MSB first) on Serial Data output (Q).

The first byte addressed can be any byte within the identification page.

If Chip Select (S) continues to be driven low, the internal address register is automatically

incremented and the byte of data at the new address is shifted out.

Note that there is no roll over feature in the Identification Page. The address of bytes to read

must not exceed the page boundary.

The read cycle is terminated by driving Chip Select (S) high. The rising edge of the Chip

Select (S) signal can occur at any time when the data bits are shifted out.

The instruction is not accepted, and is not executed, if a Write cycle is currently in progress.

Figure 12. Read Identification Page sequence

The first three bytes of the Identification page offer information about the device itself.

Please refer to Section 3.5: Identification page for more information.

M95040-DRDW4TP Datenblatt(PDF) 21 Page - STMicroelectronics